1. Field of the Invention
The present invention relates, in general, to an apparatus for collecting surface seabed sediment and an apparatus for collecting seabed sediment using the same. More particularly, the present invention relates to an apparatus for collecting surface seabed sediment able to collect sediment from a surface seabed by descending in the direction perpendicular to the seabed while preventing upper sediment from being disturbed in the surface seabed and concurrently to collect sediment from a deep region of the seabed, an apparatus for collecting seabed sediment using the same.
2. Description of the Related Art
The most fundamental and important sampling method in oceanographic research is to collect a sediment sample from a seabed. The collected sample provides raw materials for extensive research in a variety of fields, such as geology, geotechnology, geochemistry and benthology.
In particular, the seabed sediment is used as a sample for paleoenvironmental research since it properly retains information about the environmental changes of the earth. Additionally, seabed sediment is also in the limelight as an energy source since it contains submarine mineral resources (gas hydrates, manganese modules, phosphate rocks, marine aggregates, etc.).
Furthermore, seabed sediment is used as a sample when studying marine pollution or land-based pollutants.
Since seabed sediment can be used for a variety of purposes, the necessity to collect a seabed sediment sample is increasing. In addition, a variety of types and shapes of apparatus for collecting seabed sediment samples are commercially distributed.
Examples of the apparatus for collecting seabed sediment include: a grab, a dredge, a piston corer, a gravity corer, a multi-corer, and the like.
The grab is typically used at the coast in order to dredge seabed sediment. The grab is also used for dredging for the purpose of maintaining waterways. The dredge collects seabed sediment while being carried on a vessel. The dredge is typically used for collecting seabed rocks, such as manganese modules and solidified phosphate rocks, contained in seabed sediment.
The piston corer has an outer body functioning as a cylindrical body and a piston body received in the outer body, the piston body performing a piston action. A trigger weight disposed at the lateral bottom portion of the piston corer first touches the seabed, at which point in time a wound cable is unwound such that the piston corer instantaneously freely falls to be stuck into a deep region of the seabed. In this manner, seabed sediment is collected by the piston corer.
The length of the piston corer can be fabricated according to the length of a vessel or the height of a winch. It is typical that the length of the piston corer ranges from 3 to 15 m.
The gravity corer is configured such that a plastic pipe is fitted into an iron pipe functioning as a cylindrical body. The gravity corer is stuck into the seabed simply due to the weight of the gravity corer in order to collect seabed sediment.
The box corer is in the shape of a box with open top and bottom ends, with a collecting body formed of metal being positioned between the top and bottom ends inside the box. When a frame is seated on the seabed, the collecting body moves toward seabed sediment, and a shovel-shaped bottom lid moves downwards to collect the seabed sediment.
The multi corer has 4 to 8 collector bodies disposed within a frame. The collector bodies are in the shape of pipes, and are formed of plastic. The multi corer can collect seabed sediment to a depth of about 50 cm from the seabed surface.
When the frame of the multi corer is seated on the seabed surface, the multi corer is triggered, and the collector bodies move toward seabed sediment to collect the seabed sediment.
The piston corer and the gravity corer are used for collecting seabed sediment for the purpose of studies of paleoenvironment or submarine mineral resources of deep sea environments. Sediment is collected from a surface seabed using the multi corer or the box corer in order to be used as a sample from which the recent deposition environment can be known.
In particular, the operation of collecting seabed sediment must be performed twice at the same point for sediment recovered perfectly including surface sample, thereby increasing the cost and time of investigation. In addition, when the piston corer (or the gravity corer) is used, upper sediment is disturbed due to an impact caused by the corer colliding against the sediment, thereby lowering the precision of the investigation, which is problematic.
In order to solve the foregoing problems, Korean Patent No. 10-0978143 disclosed a technology of collecting seabed sediment able to collect sediment from a deep region of the seabed using a piston corer and collect sediment from a surface seabed using a trigger weight as a surface sediment-collecting corer.
However, in the related art, when the surface sediment-collecting corer is fallen freely in order to collect sediment from the surface seabed, it is difficult to make the surface sediment-collecting corer precisely fall in the vertical direction onto the seabed since ocean bottom current.
Therefore, there are potential errors when calculating the deposition rate from the collected sediment sample or when performing high-definition analysis on the collected sediment sample.
The information disclosed in the Background of the Invention section is only for the enhancement of understanding of the background of the invention, and should not be taken as an acknowledgment or as any form of suggestion that this information forms a prior art that would already be known to a person skilled in the art.